Follow Yahoo News

FILE - This Jan. 27, 2011 file photo shows an Exxon sign in Carnegie, Pa. Exxon Mobil Corp. said Friday, Feb. 1, 2013, that fourth-quarter earnings rose 6 percent to $9.95 billion with help from higher refining profit margins. The company still makes most of its money by producing oil and gas, but that end of the business was less profitable than a year ago because of lower prices and production. Exxon made up the difference in the refining business. (AP Photo/Gene J. Puskar, File)

FILE - This Jan. 27, 2011 file photo shows an Exxon sign in Carnegie, Pa. Exxon Mobil Corp. said Friday, Feb. 1, 2013, that fourth-quarter earnings rose 6 percent to $9.95 billion with help from higher refining profit margins. The company still makes most of its money by producing oil and gas, but that end of the business was less profitable than a year ago because of lower prices and production. Exxon made up the difference in the refining business. (AP Photo/Gene J. Puskar, File)